Question

Factorise the expression: $2y^2-4y-30$

• A. $(y-5)(y+3)$
• B. $(y+5)(y-3)$
• C. $(y+6)(y-4)$
• D. $2(y-5)(y+3)$

Answer 1

The correct option is D $2(y-5)(y+3)$

$2y^2-4y-30$

$=2(y^2-2y-15)$ .... taking out the common factor 2
$=2(y^2-5y+3y-15)$ .... $=2\left[y\right(y-5)+3(y-5\left)\right]$
$=2(y-5)(y+3)$